The invention is generally related to culturing of cells or tissue components, and more particularly to a culturing device and to a method for changing the level of a culture medium within a culture vessel.
Culturing devices are generally known and are used for culturing isolated cells or tissue components in a culturing media. These known culturing devices are limited for use in submerged culture systems. In a submerged system, cultivated cells are supported on the membrane of a cell culture insert and supplied with a culture solution with the appropriate nutrients by layering the solution over the cells. It is not feasible to vary the culture or growth conditions in such a submerged system.
For many experimental studies, such as for example, studies utilizing differentiated ciliary or lung epithelial cells, it would be desirable if the tissue growth conditions could be varied during the studies in order to evaluate and solve special problems. As an example, when using a conventional culturing device, culturing of cells of the respiratory tract cannot be carried out on an air-liquid interface, even if porous membranes are used, which are offered by some companies as so-called transwell systems.
In a disclosed example of an apparatus constructed in accordance with the teachings of the invention, a culturing device has at least one culture container adapted to receive and to discharge a culture medium. The at least one container has a cell culture insert removably received therein. The device has at least one supply mechanism for introducing the culture medium into the at least one culture container and for discharging the culture medium from the at least one culture container. At least one level sensor cooperates with the at least one culture container to sense a level of the culture medium for the at least one culture container. The sensor controls the supply mechanism as a function of an output signal of the level sensor representing the level of the culture medium such that a submerged culture medium supply condition and a basal culture medium supply condition can both be achieved by the device.
In another disclosed example, the at least one cell culture insert provides a horizontal culture surface within the at least one culture container.
In another disclosed example, the culturing device has at least one pair of discharge lines in fluid communication with the at least one culture container. In another disclosed example, the at least one culture container comprises a plurality of culture containers, and wherein each pair of the discharge lines is associated with a respective one of the individual culture containers. In an alternative disclosed example, the at least one culture container comprises a plurality of culture containers, and wherein at least one pair of the discharge lines is associated with more than one of the individual culture containers.
In another disclosed example, the at least one culture container is positioned so that a culture surface defined by the cell culture insert lies in a common horizontal plane.
In another disclosed example, the at least one culture container comprises a plurality of culture containers, and wherein the plurality of culture containers are connected to a common culture medium supply line.
In a further disclosed example, a supply line is connected to the at least one culture container and communicates with a riser on which the at least one level sensor is carried. In yet another disclosed example, the at least one level sensor is vertically adjustable relative to the riser.
In another disclosed example, the at least one level sensor comprises a plurality of level sensors, and wherein at least one of the plurality of level sensors includes a forked photoelectric barrier.
In another disclosed example, the at least one level sensor continuously measures the culture medium level.
In another disclosed example, the at least one level sensor comprises a plurality of level sensors, and wherein at least one of the plurality of level sensors includes a level switch that responds to a predetermined target level.
In another disclosed example, the culturing device also has an exterior housing and a plurality of discrete modules within the housing. At least one of the at least one culture container is arranged within each of the modules. A culture medium supply distribution system of the device is in fluid communication with a common culture medium supply line and with each of the modules.
In another disclosed example, the supply distribution system has a single connection in fluid communication with the at least one supply mechanism. The single connection is disposed at a lowermost elevation of the supply distribution system.
In another disclosed example, the exterior housing has a plurality of separate connectors each coupled to a withdrawal line of a respective one of the discrete modules.
In another disclosed example, each of the modules includes a discrete temperature-control housing surrounding the at least one of the at least one culture container disposed within the corresponding discrete module. Each temperature-control housing has a temperature-control medium inlet and a temperature-control medium discharge.
In another disclosed example, each temperature-control medium discharge is in fluid communication with an overflow apparatus lying in an upper region of the respective temperature-control housing. The overflow apparatus is positioned diametrically opposite to the temperature-control medium inlet within the respective temperature-control housing.
In another disclosed example, the temperature control medium inlet and discharge of the temperature-control housing of each of the discrete modules is connected in series relative to a flow path of the temperature-control medium.
In another disclosed example, the at least one culture container is disposed within an exterior housing that can provide a sealed environment within an interior of the housing. In another disclosed example, the outer housing has at least one connection for introducing a gaseous medium into the interior of the housing.
In another disclosed example, certain components of the culturing device that must be sterilized are fabricated from materials that can withstand sterilization. In another disclosed example, the sterilizable materials are selected from a group comprising at least one of glass and silicone.
In another disclosed example, the supply mechanism includes a bidirectional pump. In another disclosed example, the bidirectional pump is a peristaltic pump.
In another disclosed example, the at least one sensor comprises a pair of level sensors wherein one of the sensors controls the supply mechanism for the submerged supply condition and the other of the sensors controls the supply mechanism for the basal supply condition.
In another disclosed example, the culturing device also has a programmable controller that can control a culture medium target level transducer in a time-dependent manner. In another disclosed example, the programmable controller can adjust a target level value periodically between at least two values. One is a first level that corresponds to a liquid level that is a predetermined distance above a top side of a culture surface of the cell culture insert of the at least one culture container. The other is a second level that corresponds to a liquid level that is a predetermined distance below the first level.
In another disclosed example of the teachings of the invention, a method for culturing a culture material such as cells and tissue components includes first providing a culturing device having at least one culture container and at least one nutrient solution supply mechanism. A material to be culture is supported within the at least one culture container to expose a quantity of the culture material for culturing. Nutrient solution is then supplied for the culture material to the at least one culture container such that a liquid level of the nutrient solution can be adjusted between at least a submerged culturing level of the nutrient solution and a basal culturing level of the nutrient solution.
In another disclosed example, the method also includes the step of exposing the culture material to at least one other substance during periods where the liquid level is at the basal culturing level, and wherein the at least one other substance is selected from at least one of a solid, gaseous or aerosol-form substance.
In another disclosed example, the step of providing the supply mechanism further includes providing a sensor for sensing the liquid level and a pump controlled by the sensor for supplying the nutrient solution.
In another disclosed example, the step of supplying is carried out with the aid of a programmable controller to automatically adjust the liquid level over a time period.